ASA ACLs

Many similarities exist between ASA access control lists (ACLs) and IOS ACLs. For example, both

• Are made up of access control entries (ACEs)

• Are processed sequentially from top down

• Have an implicit deny any at the end

• Follow the rule of only one ACL per interface, per protocol, per direction

ASA ACLs differ from IOS ACLs as follows:

• ASA ACLs use a network mask rather than a wildcard mask (for example, 0.0.0.255).

• ASA ACLs are named rather than numbered. There are no numbered standard and extended ACLs, although you could name one with a number.

• By default, interface security levels apply access control without an ACL configured.